Table of Contents

JCH 20.G4 Player File Format

By FTC/HT.

I wanted to code a converter from the JCH editor file format into the format I use in my own editor, and I thought I could just as well share the structure of the JCH file format with you. The description is not 100% complete, but maybe someone will find it useful anyway. Enjoy!

I might add some more info here some other day, but don't hesitate to improve on this info yourself!

Memory Locations of various Tables and Datachunks

Arpeggio table Col 1

$18CB

Arpeggio table Col 2

$19CB

Filter table

$1ACB

Pulse table

$1BCB

Instrument table

$1CCB

Sequence Pointers (Lobyte)

$1DCB

Sequence Pointers (Hibyte)

$1ECB

Super Table

$1FCB

Sequence List - Voice 0

$20CB

Sequence List - Voice 1

$24CB

Sequence List - Voice 2

$28CB

Sequence 0 data

$2CCB

Seq data starts at +3 bytes from here

Sequence 1 data

$2DCB

Seq data starts at +3 bytes from here

Sequence …

…

Seq data starts at +3 bytes from here

Sequence Data Format

Most of the tables contain data just as it is shown from within the editor. The sequence format is not directly visible in the editor though, and therefore a brief description of this data format comes here. Each step in the sequence is represented by byte pairs (called AA and BB respectively here). Byte AA corresponds to what is found in the left column in each sequence in the editor screen and byte BB corresponds to notes or gate holds (+++) in the note column (the right column).